CVE-2025-66719: An issue was discovered in Free5gc NRF 1.4.0

This week

CRITICAL 9.1REMOTEDOWNGRADE

CVE-2025-66719 is a critical-severity flaw (CVSS 9.1) affecting nrf. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

An issue was discovered in Free5gc NRF 1.4.0. In the access-token generation logic of free5GC, the AccessTokenScopeCheck() function in file internal/sbi/processor/access_token.go bypasses all scope validation when the attacker uses a crafted targetNF value. This allows attackers to obtain an access token with any arbitrary scope.

Why this priority

Critical severity
Public exploit reference
Remotely exploitable, no login, no user action

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	9.1 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.4% (top 70%)
CISA exploited list	No
Weakness	CWE-863
Published	2026-01-23
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: free5gc

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-01-23 16:15 UTCPublished CVE record published
2026-06-17 09:57 UTCUpdated Record last modified

free5gc nrf DOWNGRADE

Affected: 1.4.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 1.4.0

1. Check installed version

apt-cache policy nrf || rpm -q nrf || nrf --version

2. No fixed release: DOWNGRADE to a release before 1.4.0 (Debian / Ubuntu)

apt-cache madison nrf sudo apt install nrf=<VERSION_BEFORE_1.4.0> sudo apt-mark hold nrf

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list nrf sudo dnf downgrade nrf-<VERSION_BEFORE_1.4.0> sudo dnf versionlock add nrf

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2025-66719?

nrf: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2025-66719 being exploited?

CVE-2025-66719 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2025-66719 affect?

CVE-2025-66719 affects nrf. Severity is critical (CVSS 9.1). An issue was discovered in Free5gc NRF 1.4.0. In the access-token generation logic of free5GC, the AccessTokenScopeCheck() function in file internal/sbi/processor/access_token.go bypasses all scope validation when the attacker uses a crafte

How urgent is CVE-2025-66719?

Priority 49/100. Critical severity; Public exploit reference; Remotely exploitable, no login, no user action

References

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